1. Field of Invention
The invention relates to an image forming apparatus including a face-up sheet discharging function for discharging a single-sided printed sheet with a printed side thereof facing up, and a double-sided printing function for printing images on both sides of a recording medium.
2. Description of Related Art
A known image forming apparatus includes a double-sided printing function for printing an image on both sides of a recording medium. When the double-sided printing is performed in the image forming apparatus, the recording medium is discharged with a side of the recording medium which is printed first facing up and with the other side thereof printed next facing down.
For double-sided printing, a reverse feeding path is required in a rearward position of a fixing unit, to reversely feed the recording medium having an image printed on one side thereof, back to the image forming unit to form an image on the other side of the recording medium.
When an image is formed on a side of a special recording medium, such as thick paper like cardboard, it is required to feed and discharge such special recording medium, with the printed side thereof facing up, through a generally straight discharge path. If the discharge path has a turn, it is difficult to feed the recording medium of the cardboard through the turn, thus inhibiting the printing of an image on the cardboard.
To form a generally straight discharge path, a rear-side plate of the image forming apparatus disposed downstream of the fixing unit in a feeding direction of the recording medium is structured to open or close. When an image is formed on the special recording medium, such as cardboard, the rear-side plate of the image forming apparatus is opened to ensure the generally straight discharge path. The recording medium is discharged onto the rear-side plate after an image is printed thereon.
As described above, the reverse feeding path is required in the rearward position of the fixing unit for double-sided printing. In addition, a generally straight discharge path is required in a rearward position of the fixing unit for printing on the special recording medium, such as cardboard. Requirements of the reverse feeding path for double-sided printing and the generally straight discharge path for printing on the special recording medium cannot be satisfied at the same time.
The invention provides an image forming apparatus including a face-up sheet discharging function for discharging a single-sided printed sheet with a printed side thereof facing up, and a double-sided printing function for printing images on both sides of a recording medium.
In various embodiments of the image forming apparatus, the image forming apparatus comprises an image forming unit for forming an image onto a recording medium, a supply path for supplying a recording medium to the image forming unit, a first discharge path for discharging the recording medium, a return path, connected with the first discharge path, for returning the recording medium to the image forming unit, a second discharge path, substantially parallel with the supply path, for discharging the recording medium, and a guide member movable from a first position to create the first discharge path and the return path to a second position to create the second discharge path.
In various embodiments of a method of forming an image by an image forming apparatus, the method comprises the steps of supplying a recording medium to the image forming apparatus, forming the image onto the recording medium, and discharging the recording medium to either a first discharge path, a return path connected with the first discharge path or a second discharge path substantially parallel with the supply path, wherein a guide member is movable from a first position to create the first discharge path and the return path to a second position to create the second discharge path.